1. Field of the Invention
This invention relates to a rubber plug for a water-proof connector which sealingly closes the gap which may be formed between the connector housing and the electrical wire inserted into it.
2. Description of the Prior Art
A conventional rubber plug of this type is as shown in FIG. 7. That is, the rubber plug 50 comprises: a cylindrical plug body 51 which is fitted on an electrical wire; a plurality of outer annular lips 52 formed on the outer cylindrical surface of the cylindrical plug body 51; and a plurality of inner annular lips 53 formed on the inner cylindrical surface of the cylindrical plug body 51. The rubber plug 50 is inserted into the cavity 56 of a connector housing 55 from the right in FIG. 5 in such a manner that the outer annular lips 52 are sealingly pressed against the inner cylindrical surface of the connector housing 55 while the inner annular lips 53 are also sealingly pressed against the outer cylindrical surface of the electrical wire 54.
However, the above-described conventional rubber plug suffers from the following difficulty: When, as shown in FIG. 8, a force acts on the electrical wire 54 at the end of the cavity 56; i.e., at the opening of the connector housing 55, to bend the electrical wire 54 laterally of the latter 55 depending on the wiring arrangement, the wall of the rubber plug 50 is compressed by the electrical wire 54 on the side to which the latter 54 is bent, thus forming a gap between the inner cylindrical surface of the cavity 56 and the rubber plug 50, and a gap between the electrical wire 54 and the rubber plug 50. As a result, the connector is no longer water-proof; that is, water may enter the cavity 56.